The following links provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File (MeF) Form 1041. You will find the Extensible Markup Language (XML) Schemas, Business Rules, and other useful information separated by tax year. Production and Assurance Testing System (ATS) - Current valid schema Tax Year Form Type 2023 1041 2022 1041 2021 1041 Modernized e-File (MeF) schemas and business rules